It's my favorite lens, next to the 50L, easily suitable for fashion and portrait work. It also shines as a lighter, more discreet lens for street photographers. Creating beautiful crisp images with wonderful bokeh in lowlight, better than the current zooms in my opinion. Here's an image paired with the 5DM3, square cropped (You can see the full image at my Website under Journal > Amara).

Oh man, there are some incredible images in this thread. A couple of my own contributions... not what I expected to be using this lens for necessarily, but the focus speed is a revelation compared to the 100mm f2.8L, and I was excited to be able to capture these: